One of the trends of development of television receivers is for larger size and higher image quality. More recently, a display device with an aspect ratio of 16:9 such as a Hi-Vision television set has come to be in a practical stage. When a television signal with a conventional aspect ratio of 4:3 as represented by the NTSC system is shown in a display device having an aspect ratio 16:9, a round image is deformed into a wide ellipse. Therefore, to depict the image correctly, a video signal converting device for converting the length of the horizontal display of the video signal is desirable. To satisfy the need for higher image quality, a noise eliminator for making the image clear is equally important.
An example of an ordinary video signal converting device is as follows. That is, the video signal data is stored synchronized with the write address signal, and the stored address is read out synchronized with the read address signal. In this device, if the frequency is different between the read address signal and write address signal, the length of the horizontal display of the video signal can be changed. This method, however, requires clocks having different frequencies, and the constitution of the device is complicated. However, interference is likely to occur between clocks. Eliminating this interference is difficult.